<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./jquery.js"></script>
</head>
<body>
    <div id="wxl">你是个天才</div>
</body>
</html>
<script>
    var tools = {
        fn:function(){
            $('#wxl').css("background","red")
            return tools
        },
        fn2:function(){
            $("#wxl").addClass('.add')
            return tools
        },
        fn3:function(){
            $("#wxl").click(function(){
                alert("还能给我整点花样")
            })
        }
    }
    tools.fn().fn2().fn3()
</script>
<style>
.add{
    width: 400px;
    height: 400px;
    font-size: 30px;
    color: white;
}
</style>